This application claims priority of European Patent Application No. 99305946.8, which was filed on Jul. 27, 1999.
This invention relates to methods and apparatus for displaying information to a user connected to a network or sub-network manager of a hierarchical telecommunications network such as are described in the Synchronous Digital Hierarchy (SDH) or Synchronous Optical Network (SONET) standards.
In a SDH or SONET network, the nodes of the network contain all the necessary functionality to route messages through the network. The network or sub-network manager supervises the operation of the network, or that part of the network which is within its management domain. One or more users are connected to the manager and have terminals which provide a view of the network, with its nodes (multiplexers) and regenerators indicated by distinctive symbols and connections between them indicated by lines. When alarms are raised, the origins of the alarms are indicated on the network view by means of a suitable colour or attribute applied to the respective symbol.
As well as providing the user with a view of the network and any alarms raised from it, the view also provides a visual interface, so that the user can select, by means of a device such as a mouse, links to configure or reconfigure.
In a SDH network, data are carried in what are called xe2x80x9cvirtual containersxe2x80x9d. The highest level of virtual container is denoted VC-4 and it can carry data at 150.336 Mbit/s. However, it can be configured to carry a number of lower level virtual containers, for example 63 VC-12 virtual containers, each of which can carry data at 2.304 Mbit/s. Typically, a VC-4 virtual container carries data from one node to another node to which it is directly connected, meaning that there are no intervening nodes, though there may be some regenerators, whereas a VC-12 virtual container typically carries data from one node to another, separated by many intermediate nodes. Thus, a VC-12, or other lower level virtual container, acts like a semi-permanent connection between a first node and a second node which is not physically directly connected to the first node; data are put into the virtual container at the first node and not unpacked until they arrive at the second, even though they may pass through several nodes on the way. Part of the function of the user at network or sub-network management level is to configure the virtual containers to provide the required semi-permanent connections and to monitor the proper functioning of the network in providing them. As such, it would be desirable to display information to facilitate such functions.
Although it is the SDH standard which is particularly described in this application, SONET networks have structures which are similar in concept, though the terminology and the exact data rates are different.
According to the principles of the invention, an improved visual interface is provided for a user at network or sub-network management level in a hierarchical network such as a SDH or SONET network. In one illustrative embodiment, the user can view the network, not only on the physical level, as is customary, but also on any of a number of virtual container levels. Thus, in an illustrative example, it is possible to view the structure of a SDH network at the VC-4 level and at the VC-12 level, as well as the physical level, and to switch between the three views. Also, where applicable, it is possible to select VC links at one level, in order to configure them, for example, to set up virtual containers of a lower level within them.